The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located inland over southeastern Texas.

The National Hurricane Center is issuing advisories on Potential
Tropical Cyclone Ten, located off the southeast U.S. coast.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

1. A tropical wave located near the coast of western Africa is
producing a large area of disorganized showers and thunderstorms.
Environmental conditions appear conducive for gradual development
of this system while it moves westward at 15 to 20 mph over the
tropical Atlantic during the next several days.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

Quote:The next African tropical wave may developA tropical wave emerging from the coast of Africa on Sunday night is expected to develop into a tropical depression by Friday over the central tropical Atlantic, according to the 12Z Sunday runs of our top three models for predicting tropical cyclone genesis--the European, GFS, and UKMET models. The wave is predicted to head west to west-northwest at 15 – 20 mph, reaching the northern Lesser Antilles Islands no earlier than Tuesday, September 5. However, the storm is emerging from Africa fairly far to the north, and has a good chance of turning more to the northwest by the weekend and missing the Lesser Antilles Islands entirely. In its tropical weather outlook issued at 8 pm EDT Sunday, the National Hurricane Center gave this new wave 2-day and 5-day odds of development of 0% and 40%, respectively.
.

The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located near Matagorda Bay, Texas.

The National Hurricane Center is issuing advisories on Potential
Tropical Cyclone Ten, located off the southeast U.S. coast.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

1. A tropical wave and associated low pressure area located just
offshore of the coast of western Africa is producing a large area of
showers and thunderstorms. This system has become better organized
since yesterday, and a tropical depression could form in a few days
over the eastern Atlantic. The low is forecast to move westward at
15 to 20 mph over the tropical Atlantic during the next several
days. Regardless of development, heavy rain is possible in
portions of the Cabo Verde Islands through Wednesday.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...high...70percent.

The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located near Matagorda Bay, Texas.

The National Hurricane Center is issuing advisories on Potential
Tropical Cyclone Ten, located off the southeast U.S. coast.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...80 percent.

1. A tropical wave and associated low pressure area located a few
hundred miles southeast of the Cabo Verde Islands is producing
disorganized showers and thunderstorms. Environmental conditions
are conducive for development, and a tropical depression could form
in two or three days over the eastern Atlantic. The low is forecast
to move westward at 15 to 20 mph over the tropical Atlantic during
the next several days. Regardless of development, heavy rain is
possible in portions of the Cabo Verde Islands through Wednesday.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...80percent.

Forecaster Blake
JM

Quote:African tropical wave 93L expected to develop
A tropical wave that emerged from the coast of Africa on Sunday night was designated 93L by NHC on Monday morning. Satellite images on Monday morning showed that 93L had a modest amount of heavy thunderstorm activity that was growing in organization, with plenty of spin apparent in the cloud pattern. Wind shear was high, 20 – 30 knots, but was expected to fall to the low to moderate range, 5 – 15 knots, on Tuesday through Friday, according to the 12Z Monday run of the SHIPS model. This should allow the wave to develop into a tropical depression by Friday over the central tropical Atlantic, as predicted by the 0Z Monday runs of our top three models for predicting tropical cyclone genesis--the European, GFS, and UKMET models. These models have been persistent in developing the new system over multiple runs, giving increased confidence that we will see a new tropical depression in the Atlantic by late this week. The wave is predicted to head west to west-northwest at 15 – 20 mph, reaching the northern Lesser Antilles Islands no earlier than Tuesday, September 5. However, the storm will probably gain enough latitude this week to allow it to feel the steering influence of a trough of low pressure passing to its north, resulting in a track that would miss the Lesser Antilles Islands. Only about 10% of the 70 members of the 0Z Monday GFS and European model ensemble forecasts showed the wave affecting the Lesser Antilles next week. However, it is too early to put much confidence in the system’s long-range track until it consolidates into a tropical depression. In its tropical weather outlook issued at 8 am EDT Monday, the National Hurricane Center gave this new wave 2-day and 5-day odds of development of 30% and 70%, respectively.
.

The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located near Matagorda Bay, Texas.

The National Hurricane Center is issuing advisories on Potential
Tropical Cyclone Ten, located off the southeast U.S. coast.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...medium...60 percent.

1. A tropical wave and associated low pressure area located a few
hundred miles southeast of the Cabo Verde Islands is producing
disorganized showers and thunderstorms. Environmental conditions
are conducive for development, and a tropical depression could form
within the next few days over the eastern Atlantic. The low is
forecast to move westward at 15 to 20 mph over the tropical Atlantic
during the next several days. Regardless of development, heavy rain
is possible over portions of the Cabo Verde Islands through
Wednesday.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...high...80percent.

The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located just offshore of the middle Texas coast.

The National Hurricane Center is issuing advisories on Potential
Tropical Cyclone Ten, located just offshore of the North Carolina
coast.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...40 percent.

1. Showers and thunderstorms associated with a low pressure area near
the Cabo Verde Islands have become better organized since yesterday.
Environmental conditions are conducive for development, and atropical depression is expected to form in 2 or 3 days over the
eastern Atlantic. The low is forecast to move generally
west-northwest at 15 to 20 mph over the tropical Atlantic during the
next several days. Heavy rain is possible over portions of the Cabo
Verde Islands through Wednesday.
* Formation chance through 48 hours...high...70percent.
* Formation chance through 5 days...high...90percent.

Above: 93L near the Cabo Verde Islands off the coast of Africa, as seen on Tuesday morning, August 29, 2017, by the MODIS instrument on NASA's Terra satellite.

A tropical wave located near the Cabo Verde Islands on Tuesday morning has the potential to be Tropical Storm Irma late this week, and could pose a long-range threat next week to the Lesser Antilles Islands. Satellite images on Tuesday morning showed that 93L had a modest amount of heavy thunderstorm activity that was steadily growing in organization, with a prominent low-level spiral band on the south side and plenty of spin apparent in the cloud pattern. Conditions were favorable for development, with sea surface temperatures (SSTs) near 28°C (82°F)—more than 1°C (2°F) above average, moderate wind shear of 10 - 20 knots, and a moist surrounding atmosphere with a mid-level relative humidity of 70%. Wind shear was predicted to be in the low to moderate range, 5 – 15 knots, on Tuesday through Sunday, according to the 12Z Tuesday run of the SHIPS model. This should allow the wave to develop into a tropical depression by Friday over the central tropical Atlantic, as predicted by the 0Z Tuesday runs of our top three models for predicting tropical cyclone genesis--the European, GFS, and UKMET models. These models have been persistent in developing the new system over multiple runs, giving increased confidence that we will see a new tropical depression in the Atlantic late this week.

The wave is predicted to head generally west-northwest at 15 – 20 mph through Friday, then assume a more westerly or even west-southwesterly track over the weekend, as a strong ridge of high pressure builds to the north of 93L. This would potentially bring 93L into the Lesser Antilles Islands as early as Tuesday, September 5, as predicted by the 0Z Tuesday run of the European model and most of its 50 ensemble members. The GFS model was much less concerning, with its 0Z and 6Z Tuesday runs predicting that a strong trough of low pressure would turn 93L to the northwest early next week, resulting in 93L missing the Lesser Antilles Islands by more than 500 miles. It is too early to stress out about the European model’s solution until 93L consolidates into a tropical depression, though, as typical errors in a 7-day track forecast are well over 500 miles. In its tropical weather outlook issued at 8 am EDT Tuesday, the National Hurricane Center gave 93L 2-day and 5-day odds of development of 70% and 90%, respectively.
.

The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located just offshore of the middle Texas coast.

The National Hurricane Center is issuing advisories on Potential
Tropical Cyclone Ten, located near the Outer Banks of North
Carolina.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

1. A low pressure area located just west of the Cabo Verde Islands has
become better defined since yesterday. Any significant increase in
the associated thunderstorm activity would result in the formation
of a tropical depression within the next day or two. The low is
forecast to move generally west-northwestward at 15 to 20 mph over
the tropical Atlantic during the next several days. Heavy rain is
possible over portions of the northwestern Cabo Verde Islands
through tonight.
* Formation chance through 48 hours...high...80percent.
* Formation chance through 5 days...high...90percent.

The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located just offshore of the upper Texas coast.
The National Hurricane Center has issued the last advisory on
Potential Tropical Cyclone Ten, located just east of the Outer Banks
of North Carolina.

1. A low pressure area is located just west of the Cabo Verde Islands.
This system continues to become better organized, and any
significant increase in the associated thunderstorm activity would
result in the formation of a tropical depression within the next day
or two. The low is forecast to move generally west-northwestward at
15 to 20 mph over the tropical Atlantic during the next several
days. Heavy rain is possible over portions of the northwestern Cabo
Verde Islands for a few more hours.
* Formation chance through 48 hours...high...90percent.
* Formation chance through 5 days...high...90percent.

Forecaster Cangialosi/Brown

Track not unlike that projected for Harvey at this point in its travels across.

Up to 33mph with no noticeable change in pressure.

Far too early to project accurately except to know this is more than just likely to develop and bears watching for now.

The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located over southwestern Louisiana.

1. Satellite images indicate that the low pressure area a couple
hundred miles west of the Cabo Verde Islands has become better
organized overnight, and advisories will likely be initiated at 11
AM EDT on a tropical cyclone. The system is forecast to gradually
intensify and move west-northwestward to westward at about 15 mph
over the tropical Atlantic during the next several days.
* Formation chance through 48 hours...high...near 100percent.
* Formation chance through 5 days...high...near 100percent.

Forecaster Blake

WTNT22 KNGU 300900
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/FLEWEACEN NORFOLK VA/281900Z AUG 17//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTNT21 KNGU 281900)//
RMKS/1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 15.4N 28.8W TO 16.6N 35.9W
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT
IMAGERY AT 300600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.4N 28.9W. THE SYSTEM IS MOVING WESTWARD AT 17 KNOTS.
2.REMARKS:SUBJ/TROPICAL CYCLONE FORMATION ALERT 300900Z AUG 17//
SATELLITE IMAGES SHOWS A TROPICAL WAVE AND ASSOCIATED AREA OF
LOW PRESSURE IS LOCATED ABOUT 120 MILE WEST OF THE CABO VERDE
ISLANDS. SHOWERS AND THUNDERSTORMS PRODUCED BY THIS SYSTEM
CONTINUE TO BECOME BETTER DEFINED AND ARE GENERATING WINDS OF 25
TO 30 KT. ANY FURTHER INCREASE IN CONVECTIVE ORGANIZATION WOULD
RESULT IN THE DEVELOPMENT OF A TROPICAL DEPRESSION. THE SYSTEM IS
EXPECTED TO MOVE WEST-NORTHWESTWARD AT 15 TO 20 KT DURING THE
NEXT FEW DAYS.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 310900Z.//NHC Atlantic Ops‏Verified account @NHC_Atlantic7m7 minutes ago

NHC will be initiating advisories at 11 AM AST on Tropical Storm Irma, located west of the Cabo Verde Islands.